Method of making a molded article



Examiner 106-75 113 Reference Jan. 17, 1933. A, M. HERBSMAN METHOD OF MAKING A MOLDED ARTICLE Filed June 6, 1931 Patented Jan. 17, 1933 PATENT OFFICE O! moron PARK, CALIFORNIA.

men 01' W6 A IOIJDED AB'I'IOIJI Applicatlon fled June 6. 1931. mm Io. 548,488.

. This invention relates in general to molded articles and to methods of manufacturing these. Particularl the invention relates to such articles as in ude a relatively nonadhesive aggregate, and a binder, WhlCh causes adjacent particles of the aggregate to adhere together. The invention also relates to methods of producing such a binder.

In molding articles of certain kinds of a ate it has in the past been found dlflicu t to orm a binder which will hold fast in the presence of moisture.

It is accordingly an ob]ect of my invention to rovide a blnder having a broad application and which is waterroof.

There is a very large rials having the qualities of insulatmg against electricity, heat, sound, or a comb1- nation of these. In a large measure the demand is met by insulating materials manufactured from minerals, and principally mica, asbestos and exfoliated vermiculite, the latter bein known in the trade as Zonolite. These insulating materials are manu ac ure in various shapes by breakin up the mineral from which they are formed mto small pieces or particles, mixing these pieces with a suitable binder, molding the mixture and rmitting it to dry so that .it will retain the shape given it in the mold. The binder most commonly used with these minerals has been sodium silicate, and one of the greatest difliculties with this binder has been that in the presence of moisture it loosens up and allows the insulating material to disentegrate.

It is accordingly another object of my invention to provide a suitable binder for use in the forming of insulating materials from natural insulating minerals, such as mica, asbestos and zonolite, which will be moistureproof and accordingly cause these materials to retain their shape in the presence of water.

The recent development of the sound film industry has brought out the necessity for eliminating all extraneous sounds from the sound studios where the pictures are produced. To date one of the best sound insulating materials tried out for'efiecting this purpose has been slabs of zonolite which consist of an aggregate of exfoliated zonolite emand for matefragments held to ether in slab formation by a suitable bin er. Hitherto no binder has been roduced which will hold the zonohte toget er in the presence of moisture and yet give the maximum sound insulating effect which is possible with the zonolite. As

much of this insulating material must be air studios the need for such a -L used in open binder has been pressin It is accordingly a further object of my invention to provide a method of binding zono- Fig. 2 is a rspective view of an insulating slab which e mold Fig. 1 is adapted to form.

Fig. 3 is a diagrammatic fragmentary cross sectional view throu h a furnace used in carrying out the metho of my invention.

Fig. 4 is a diagrammatic fragmentary perspectlve view lllustrating the manner in which the wall of insulating slabs may be formed by nailing zonolite slabs shown in 'Fig. 2 onto wooden studs.

Fig. 5 is a fragmentary diagramatic perspective view illustrating the manner in which zonolite slabs, formed according to my invention, may be used as furring in a solid concrete wall construction.

Referring specifically to the drawing, theapparatus used in carrying out the method of my invention comprises a series of molds 10 and a furnace 11. Each of the molds 10 includes a bottom plate 15 which fits into a groove 16 formed 1n inner faces of side plates 17. The side plates also have grooves 18 which receive mold end plates 19. Formed in extending ends of the sidebars 17 are bayonet slots 20 which are adapted to receive bars 21 having bent ends 22 which retain the be; a, 5. 4a

bottom plate, side bars and end bars of the mold in assembled relation. Formed outwardly on the side plates 17 are lugs 25 which hingedly carry top latches 26. When the 5 arts thus described of the mold are assemled together a molding chamber 30 is provided, side and end walls of which are dis: posed parallel. Adapted to extend down mto the chamber 30 and make a reasonably t ht fit therewith is a top 31. This top is a apted to be engaged by the latches 26 as shown in Fig, 1 so as to compress a body of material in the chamber 30.

The furnace 11 may be of any desired construction and provides a furnace chamber 40 into which a series of burners 41 inject buming fuel so as to maintain a tem erature therein which is controllable. As 5 own in Fig. 3, the molds 10 are adapted to be stacked one upon another in the furnace 11 to be heated.

The method While the method of my invention is adapted to be applied to the binding together of particles of any material which is sufliciently heat resistant to go through a heating process without change of form or composition, it is particularly adapted for the inding together of zonolite fragments in the forming of insulatin materials. Ac-

cordin ly, .the following escription of the meth will cover the use of the method for thisp ose.

Broa y sta ed, my method might be said to consist in the formation of an insoluble silicate in the open aces between fragments of zonolite, presse together, so that this silicate will adhere to the surfaces of the zonolite and cause the particles of the latter to be bound to ether in a unitary mass which will keep its Form unimpaired by the presence of moisture. The method may be carried out by the use of several different combinations of chemicals, but the preferred manner of carryin out the method for the formation of zonollte slabs is as follows:

First, a mixture is made of the following ingredients:

5 Parts by lght Silicate of soda, 40 B 750 Iron or aluminum hydrate 25 Borax 100 This mixture may be termed the binder mix and is in turn mixed with 500 parts by weight of nolite. Such a quantity of this final mix is pu 1n 0 each of the molds 10 as will form a slab 50 of zonolite when the .top 31 of the mold is pressed downward thereon and locked in place by throwing the latchcs 26 upwardly. I have found that the best results are obtained when the quantity of final mix placed in the mold is such that when the. top has thus been pressed down and latched a pressure of approximately one pound per square inch is placed on the mix. When the molds have thus been fill .1 they are stacked in the furnace 11 as shown in fig. 3 ali dfheated to a tem 11 0 900 or a period of a ut e1 lit ours. ms of this time the molds ar removed from the furnace, allowed to cool, and then knocked down and the slabs 50 removed therefrom. The heating process through which the mixture is put, in forming the slabs '50, causes a chemical reaction between the silicate of soda and iron or aluminum hydrate so that an insoluble iron or aluminum silicate is formed which securely binds the particles of zonolite in the slab 50 toso gather and which is not affected by water. he borax acts as a flux and facilitates the flowing of the insoluble silicate into intimate relation with the particles of zonolite, thus causing the zonolite particles to adhere tenas5 ciously to each other.

Furthermore, the slab thus formed not only holds its form in the presence of water, but can be'sawed and nailed incidental to buildin operations. Incase an iron hydrate is used 1n the binder mix, the resulting binder has a chemical composition of a double compound of iron silicate and a hero iron silicate. Both of these compounds are insoluble in water.

While I prefer to use sodium silicate in the binder mix, it is to be understood that any soluble silicate may be used in this mix with an ox'd'l e or li droxide or car 11 of manaimkmfiifrmm 10o res e process, at is, the formation of suitable insoluble silicates, may be obtained by the substitute chemicals suggested as well as by those set forth in the preferred form of the method. In fact, it is not desired to be limited even to the substitute chemicals named above, as a certain measure of satisfactory results can be obtained by the use of many mineral oxides, hydrates or carbonates with a water .soluble silicate in such a manner as to form an insoluble silicate binding the particles of zonolite into a solid mass.

It is to be understood that the proportions given and the conditions for carrying out the method of my invention are illustrative only, and various changes might be made in these without departing from the spirit of the invention or the scope of the appended claims.

For the purpose of illustrating the use of the slabs 50 I have shown in Fig. 4 a series of slabs 50 nailed onto studding 51 so as to serve as an acoustic insulating wall in a studio or serving as a general insulation and plaster base for a wall in a building.

Fig. 5 shows the use of slabs 50 as a furring for a concrete wall 52. In the example shown, the slabs 5 0 are provided with 118.115

55 which are secured as by wires 56 to the wall 52. When thus secured in place, the

rature of 1092 we. (JOMPUSIHUNS,

COATING R PLASTIC I slabs 50 form an excellent furring water and steam pipes or for boiler surfaces and the like.

It is also desired to point out that this material might be manufactured in solid cakes and made into slabs or wall board by sawing, and the material thus formed could be trimmed down to shape by a planer in a similar manner as wood is shaped.

Another manner in which the mixture of zonolite and binder might be a plied is where it is desired to make an unbro en cover of insulating material around an element such as arefrigerator or boiler, in which case the element to be covered would have the mixture of aggregate and binder lastered against the outer surface thereof. fter the desired coating has been thus built up, it is heated in an oven, or by flame a plied to its outer surface as by a blow torch, f or a sufficient length of time to transform the binder mix into an insoluble silicate and thus complete rformance of my method.

In the ormation of continuous insulation in this manner it is sometimes advantageous to slag the outer surface of the insulating material b application of an acetylene torch thereto, w ic forms a black, hard coating over the entire outer surface of the insulating material.

From the foregoing description of a preferred form of the method of my invention, as

well as a number of variations therein included in the invention, it will readily be seen that the term molding when used in defining the method of my invention is to be broadly construed so as to cover and include any application of force to the mass of aggregate to be bound together which will cause one or more surfaces of said mass to assume a desired conformation. It will be readily seen that this force .may consist of the force of gravity of the mass itself which naturally causes it to conform to a surface upon which the mass is resting.

What I claim is: I

1. A method of making a molded article which consists in mixing an aggregate of refractory material with a water soluble silicate, and a material ca able of uniting with said soluble silicate to orm an insoluble silicate, molding said mixture to a given shape,

Cross Reference and heatin the article thus molded to form said insolu le silicate and fuse this to unite the particles of said aggregate.

2. A method of ma g a molded article which consists in mixing an aggregate of refractory material'with a flux, a water soluble silicate, and a compound capable of uniting with said soluble silicate to form an insoluble silicate, molding said mixture to a 'ven shape, and heating the article thus mol ed to form said insoluble silicate and fuse this to unite the particles of said aggregate.

3. A method of making a molded article which consists in mixing an a gregate of re-' fractory material with an a ali silicate, a water insoluble, oxide or hydroxide, and a flux, molding said mixture to'a given shape, and heatin the article thus molded to cause a combinationbetween said silicate and said oxide or hydroxide to form an insoluble silicate which will bind the particles of said aggregate together.

4. A method as in claim 3 in which said alkali silacate is sodium silicate.

5. A method of making a molded article which consists in mixin an aggregate of refractory material with orax, a water sol- -uble silicate, and a compound capable of uniting with said soluble silicate to form an insoluble silicate, molding said mixture to a given shape, and heating the article thus molded to form said insoluble silicate and fuse this to unite the particles of said aggregate.

6. A combination as in claim 3 in which borax is used as a flux.

7. A combination as in claim 3 in which said alkali silicate is sodium silicate and in which borax is used as a flux.

8. A method of making a molded article which consists in molding an aggregate under ressure and while sa1d aggregate is thus mol ed producing in the interstices between adjacent particles of said aggregate a double compound of metallic silicate and a borometallic silicate so that these compounds adhere to said aggregate and bind the particles thereof together.

9. A method of making a molded article which consists in molding an aggregate under pressure and while said aggregate is thus molded producing in the interstices between adjacent particles of said aggregate a double compound of iron or aluminum silicate and a bore-metallic silicate so that these compounds adhere to said aggregate and bind the particles thereof together.

10. The method of making a molded article which consists in molding zonolite par-.

' 11. The method of making a molded article which consists in moldin zonolit parholes, and while said zonolite is thus molded,

exam: We

producing in the interstices between adjacent particles an insoluble silicate and fusing said silicate so. that this adheres to the various particles. i

5 12. A method of making a molded article which consists in molding a mass of particles of a refractory material and producing among said particles a fused insoluble silicate.

13. A method of making a molded article which consists in molding a mass of articles of a refractory material and providing among said particles an insoluble silicate, the melting point of which is lower than that of said refractory material, and fusing said silicate.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 29th day of May, 1931.

ABRAHAM M. HERBSMAN. 

